1. Field of the Invention
The present invention relates to a light module, and more particularly to a high-power light module packaged with both solid and fluid packaging materials.
2. Description of the Prior Art
A cold illumination LED has the advantages of low power consumption, long device lifetime, no idling time, and quick response speed. In addition, since the LED also has the advantages of small size, suitability for mass production, and ease of fabrication as a tiny device or an array device, it has been widely applied in display apparatus and indicating lamps used in information, communication, consumer electronic products, and automotive industry, such as, cellular phones, as backlights of personal data assistants, outdoor traffic signal lamps or various outdoor displays, even as a components in the highly popular liquid crystal displays.
FIGS. 1 and 2 are each a cross section diagram showing a conventional LED module, respectively. As shown in FIG. 1, the conventional LED module includes a substrate 10, a plurality of LED units 12 positioned above the substrate 10, and an encapsulating material layer 14 disposed on the LED unit 12. As shown in FIG. 2, the conventional LED module includes a substrate 16, an insulating layer 18, a printed circuit board 20 positioned above the substrate 16, and a plurality of LED package bodies 22 disposed on the printed circuit board 20 and electrically connected to the printed circuit board 20. The LED package body 22 is constructed by forming the encapsulating material layer 24 via molding or sealant injection, and the entire LED module is then formed by aggregating each of the LED package bodies 22 on the substrate 16.
In conventional techniques, the substrate can be a lead frame or a printed circuit board (PCB), and a singular or plural LED chips are fixed onto the substrate. The encapsulating material layer is composed of mixtures containing resin, wavelength converting materials, fluorescent powder, and/or light-diffusing materials and packaged onto the substrate by a molding or sealant injection method. In order to protect the LED chip and wires, the encapsulating material layer is composed primarily of robust and enduring materials. Hence, it is disadvantageous that as the encapsulating material layer gets more rigid, the stress level of the overall package structure will increase accordingly, which will easily cause the encapsulating material layer to break in half or detach from the substrate and decrease the reliability of the product. Furthermore, the conventional encapsulating material layer has poor heat dissipation ability and a poor UV resistance, and thus a yellowing is likely to occur.
In case that the entire LED module is formed by aggregating a plurality of LED package bodies on the substrate, the volume of the resulted LED module will be relatively large and heat dissipation is still poor, resulting a short life time. With respect to the package with a singular or plural LED chips fixed onto a substrate which may be a lead frame or a printed circuit board (PCB), the substrate supporting chips is usually large and comprises of heat conductive or further electric conductive material. The packaging is performed by a molding or sealant injection method. Thus, the volume after packaging is much larger than a general LED. The encapsulating material still has disadvantages of tending to be yellowing and having low heat dissipation properties.
Therefore, a good LED package structure is still needed.